UART Synchronization with CC2640R2

In our customised board we are using imx6sl processor and Ti's CC2640r2 MCU which is intefaced via UART. As per our use case processor(imx6) will send data packect to cc2640r2 and then CC2540r2 will update the same data in advertisement packet. but we are facing an issue that whenever processor is sending data packet to cc2640r2 , MCU stops responding but when we are echoing the same packect, MCU starts responding . I also tested the same by connecting U2UC board and cc2640r2 the MCU is able to recieve, parse and respond to the recieved packet. following are my test cases. Test Case: 1 -> CC2640r2 connected to U2UC board and data packet being sent by the help of Teraterm. result device is able to update the parameters in advertisement packet. 2 -> CC2540r2 connected to processor sending data packet by the help of ECHO command result device is able to update the parameters in advertisement packet. 3 -> CC2640r2 connetced to processor sending data packect recived by processsor to CC2640r2 result device is parameters are not getting updated but MCU is not going to halt mode. now if I repeat 2 number use case then also device not responds. Plese suggest me what possible changes do I need to make so that MCU is able to recive data packect.